A 1.2 V, 3.0 ppm/°C, 3.6 μA CMOS bandgap reference with novel 3-order curvature compensation

Abstract

This paper presents a bandgap reference with a high-order curvature compensation circuit which can improve the temperature coefficient (TC) in a wide temperature range. The proposed compensation circuit includes a second-order and a third-order curvature current generators as well as an I-V converter. These two curvature currents are achieved by utilizing the exponential behavior of sub-threshold MOSFET and used for compensating the high-order temperature dependence of BJT base-emitter voltage via I-V converter. The proposed BGR is implemented in a CMOS 0.18 μm process with the active area of 0.056 mm2. Measurements on ten samples showed that at the minimum supply voltage 1.2 V, the TC varies from 1.7 to 6.9 ppm/°C over a temperature range of 170 °C (−45 °C–125 °C) with an average value of 3.0 ppm/°C and the total current consumption of 3.6 μA at room temperature. In the supply voltage range of 1.2–1.8 V, the line regulation (LR) is 0.025%/V.